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sse' Gom-mmtemm am 'ieri of Re Ssuer eti-fd man 'ffrtiaa fum my 31, 15MLl mea Mawr. 2, im?.

mes, residing at istng in wnsidemba quantities in se'ap ik@ @mmtjg of Cosk .and am? wher farma of manganese seel is wned Garmin. new ms il- Methods @i @ic-Qi, of which iba son.

'P s, have i; Josiah; have been Heade im avoiding vthis mss. Thess haw .gnray been aong he Mms ai 1" 4elwirommm in whiff@ he Q el' is melsd, with A plyng .sbstanfses than manganes,

11,@ he imied amuunt e'ec df.; hat nes @am access to the batik;

'u pmu; of the oxidized Lrmngane-se hat f awjf been 'amen up by the Slag, and y the mng'anes to the jectoml huir, partiaiy, if 1 e "immune is mp'myed @kei-fic' if mi w wh, so that oxdw we the ik@ @nu agg in the immediate prevneai; Som-(se, if not thmughu-t Mes foi/'ng undexb exemmemcing materials amd.

in :Veiaimng the Swed by my' pz'esent dicuts mentn a minimum the uxdation 4, um of nxsmgan :ay Wmij/ 'pyevens vaporzaufvmagfe mi SOW) Mon, and reduces time time ement, besxdas pe'miting fr0-manganese. to be` melted' Wh tu@ Semp, m 'the'ebj/ simptes the app-nii ius raqus. and reduces imm employed, the process invoves mareasv ing the manganese constituent for some ultimate use to be made of the product, such as alloying with a larger heat of blown metal.

It is well recognized that the lheat conductivit of manganese steel is extremely low, in act so low that when pieces having any materia-'l thickness are introduced cold into. a furnace havingr a melting tempera D ture, the skin of the piece quickly heroines fluid and runs long before the interior is heated. `T'hus it manganese steel S'crap which consists ofrisers. spruesand crop ends of ingots, blooms. billets, and the like` ischarged cold int( a 'furnace in which amelting ten'iperature otl manganese steel is maintained. even with or withouta .slag or a hath ot' iron or steel. the skin of' these chunks of scrap will hecome l'luid quite'rap- ,idly and the manganese will have opportunity to oxidize or to imite with the'slag. The addition of reducing` agents to the slag will serve to lin'ecipitate the manganese hut it will also malte necessary the decarhuriza4 tion of the steel as the carhon content will change. 'l`o decarhnrize the Steel neccs sarily involves a high temperature and con- Se( uentloss ot' manganese. i

Vhile proceeding: upon lines which maintain a n onoxid'izing enyironmentl tolfthe hath, so far as the same may he ohtained hy of metal; on the contrary. the temperature of the heat source and ol' the lath is de veloped in Stages. and the manganese lying upon the surface ol' the pieces ol` scrap or in the immediate presence oi' the arc is protect ed equally .with that contained on the .in teriorof the pieces. or throughout the entire bath. At. the final heat stage.. which may be sutl'icient to induce oxidation. precautions will have heen taken to atl'ord the P freatest possihle protection to thel metal, and the telnperature will exist only for the shortest time. being developed immediately preceding the drawing ot' the furnace.

In carrying out the invention. an electric furnace is preferably employed hecause of the Vfacility wit-h which atmosphere can he excluded therefrom. hut any other method of heating which combines thc feature ol' e eluding oxidizingr influences vwith controlled tempegature of the heat source ma \v he eniploved.

Having charged the -t'urnace with the scrap or other torni of? mangano-ie Steel, cara is exercised to avoid a temi'ierature at the arc in excess ot i2000 l". until the entire, hath has reached thatl temperature.y and untilLv means hare heen provided or are ready torapplication to protect der the further increase of temperature. Even the temperature of M1100 F. is preferahly approached gradually or in Stages, by first using even a lower temperature in the arm and developinga the sanne throughout the hath and gradually increasing; the temperature ot' the are o r heat Source. and in this way working: up to i2000 l". in the pre Jerred procedure. an initiai temperature Stage as low Gitti@ if. may tiret. he developed with adif'antagfe, as hy Margine; cold Scrap into a cold furnaceand deveiogz-ing an are at such voltage as xviii product);` heat ot 'Substantially tif "to l".. and maintaining this heat until the iole body of the metal is at a homogeneoi tez'nperature. i'ret'erahiiy the electrode is so adjusted as 'to permit the creation ot' an arc ot short length :is possible and to bring the' arc into close prox iznity with the scrap. The voltage heine' low assures the conduction ot' Cinergy of not too vigorous action. which will prevent any hut a gradual heat applicati-on to the scrap. Then the arc is increased and the temperature increased hy stages through SHQ (04.30 etc. up to l/)lllf if. fir. ii" the furnace has not t'ully 'cooled down from a nrevioui-i' heat hut. stands at a temperature of. say. 156Go F.. afterhavingi heen opened and had nece@ .sary repairs made to its-lining. the cold may he charged into the furnace hy whit? time the temperature will have fallen to illtio or, T000 "..then the turnace rinsed and permitted to stand cloaed without aniiriu tion ot additional heat until the charge has ahsorhed heat from 'the walis ot' the furnace and heen hrouffht to an initial temperature oft'. say; not?" in. after which the are wilt he developed with restricted ,witzige to create a temperature equal to that ot' the scrap and furnace. i. e, 5000. if.. and then .levelopeii in successive stages ot' temperature. which .viii gradually work the heat ot' the hath through ollon T00?, etc.. up to i200" if.

Not only in attaining' the temperature o? around 12000 l". hut aiso iu attaining: tenu peratures ahfoiv 1:2000 F.. is the temperatura ot' the hath raised grradnallv or in stages. in

the sense that the temperature of the vhf-at' source is controlled. and` therefore. the tem perature in any one part niaterialiy in e-rcess of that of the '.vhoie hath carefully avoided. -'l`his reali-aint is ohserved even until the hath reaches about ifaloli". At about 22110 F'. the charge of manganese evteei will hegjin to assume a mushy or hroiien down condition. and het'ore going nnichhcyond this state. vthere shouid he prorieion made for resistin; auch oxidation as might oci-ar against oxidation 'any' l. lll:

liis

from even the limited proportion of oxygen that is unavoidably present within the ,furnace.' These precautions will be in the nature of a basic slag, which, or the slagging fluxes for production of which, may be added either-'at this stage or at an earlier stage, or even at the time of charging the furnace or partly at the time of charging and partly as the increased temperature stages are -attained if observation shows the covering of slag to be insufficient. Up to this temperature, i. e. 22000 F., serious oxidation of the manganese will not take place; much` less will there have been much loss by vaporization.

At about 2400l F. the manganese steel will be completely fused, and the sla-g will exist at the top and form the protecting covering against oxygen that may be present in y the unfilled space of the furnace. Thebatn may safely be retained. at this temperature for such ar length of time as may be necessary pending preparations for tapping the furnace. This tapping may be made into a. pouring ladle for casting into billets, or molds, or for transfer to and alloying 'with a heat of blown metal. In the'latter instance additional manganese will be added, as explained below. J

When t-he metal'is ready to be tapped, the'4 temperature may be cautiously increased above substantially 240()o F. to render the y bath 'highly .fluid, but this increase will be relatively harmless because the bath is now Well protected, and the increased tempera-l ture will exist for but a short time.

I have found that by proceeding as above outlined the loss of manganese in the reuse of manganese steel scrap 'will 'be reduced to a very small percent-age of the original manganese content, and, indeed, to such a small percentage as Will permit the reuse manganese steel as such, and without restoring any of its manganese content, However, the restoration of the proportion ci manganese can be readily accomplished by charging into the furnace a suitable quantity of ferro-manganese, the quantity of which is readily estimated because the analysis of the manganese steel scrap originally charged is accurately known, and its loss of manganese has been so well controlled that it will be of a constant and readily estimated small percentage.

It the bath of manganese steel obtained as above describedis to be used 'for alioying a. larger body oi blown metal, for instance, in the production ot" manganese steel, it will, of course, he necessary to add a suitable per- 'centage of tei games-e, The addition of manganese it purpose can belnade in the same tornai with. melted scrap and at a temperature stage that will practically avoid losstby oxidation. Thus a very great saving in this now expevr faire alloying element will be effected, and the use of a. separate furnace and the firing and labor cost ot' serving the same will be avoided.

l do not claim in this application the method ot producing manganese steel by the use ot' the subject-matter of the present application, as thisis described and claimed in my application Serial No. 151,882, filed March 2, 1917.4

I claim:

1. The improvement in the art of recover-- ing manganese steel, which consists in applying heat to the steel at an initial ternperatnre below the oxidizing temperature of manganese, and at successively imreasingr stages of temperature until the entire mass is gradually brought to the melting point oi.t manganese steel. i

2. The improvement in the art ot' recovering manganese steel, which consists in applyingir heat to the steel at an" initial temperature below the oxdiaing temperature of manganese, and at successively increasing stages of temperature until the entire mass is gradually brought to the melting point of manganese steel; the process being carried on in a relatively inert environment.

3. The improvement in the art of recovering manganese steel, which consists in applying heat to the steel-at an initial temperature below the oxidizing temperature of manganese, and at successively increasing stages of temperature until the entire mass is gradually brought'to the melting point ot' manganese steel; the process being carstages of temperature until the entire mass Y gradually hroughtrto the melting point ci manganese steel; the hath being maintained at about the melting temperature until the metal is needed. arid-the temperature being increased to the point ot high fluidity ci" the metal immediately preceding the tappingr oi' the furnace. Y

The improvement in the art oi recovering manganese steel, which consists in heating the charge oinietal by an initial application of Aheat not over 705V F., and then increasingy the applied heat in stages to bring the entire mass gradually to the melt-ing point ,of the steel.

6. The improvement in the 'art of recovering mangi; se steel, which consists in heating the charge of metal by an initial aplilication of lil-eat not over 7Go@ F., and

then increasing the applied heat in stages to bring the entire i'. ass gradually to the melting. point of the steel, maintaining the term pelaturt` at about the melting point until the metal is needed, and raising to the teinperature ot high fluidity just previous to tapping.

7. The improvement. in the. art of 'rennt/H -eriug manganese steel. which Consists in (levelopingf an initial temperature of below 700 l". throughout the charge of-metal, gradually increasing the temperature otthe hath to 1200" F.. and thereafter raising the` ingaan" is gradually brought to the melting" ot manganese stool; additional manD being supplied to the .bath in thc 4melting furnace.

E). The improvenient in the art of recoif-- .ering manganese steel, which consists in aaiplying heat to the stoel aty an initial bein peratui-e. below the oxidizing temperature oi manganeso, and atsuecessively incroasing of temperature until theentiro mass is 2gradually brought to the melting point ot' manganese stoel, the oath boing maintained at about the melting temperature until the metal is noedled.I and the temperature being increased to the point of high fluidity ot' the iiietal immodiately preceding the tapping ot' the turn ce; additional manganese being;r suppliied -to the bat-l1 in the, melting furnace.

Signed at Chicago, 'lllinoiy this 5th day of' Octobffi, 1921.

WESLEY G. NCHGLS. 

